Selectivity of Entomopathogenic Fungi to Chrysoperla externa (Neuroptera: Chrysopidae)

Abstract

We aimed to evaluate the selectivity of entomopathogenic fungi to larvae of Chrysoperla externa (Neuroptera: Chrysopidae). For this purpose, Beauveria bassiana (strain ESALQ PL63), Metarhizium anisopliae (strain ESALQ E9) and Metarhizium rileyi (strain UFMS 03) were assessed at different concentrations (1 × 107, 1 × 108 and 1 × 109 conidia mL−1). The control treatment consisted of distilled water and Tween80 0.01. The treatments were applied with a Potter spray tower using two different methodologies: direct application (DA) and dry film (DF). Up to 96 h after application, no treatment provided a larval mortality above 3%. After 120 h, only B. bassiana induced significant mortality in all instars, with rates of 26%, 17% and 10% for first, second and third instar larval periods, respectively. There was no difference regarding to the application method or concentration of conidia. The percentage of individuals that revealed changes in the length of the larval and pupal periods varied among different treatments with entomopathogenic fungi and control treatments, application methodologies and concentrations. Despite B. bassiana revealing a higher mortality than M. anisopliae and M. rileyi on larvae of C. externa, these three entomopathogenic fungi may be used in association with C. externa for sustainable pest management.

Agro-Ecological Management of Coffee Pests in Brazil

“…Recently, Macedo et al (2020) discussed the possibilities of disseminating B. basssiana spores by bees during coffee blooming and its contributition to the regulation of CBB populations. The main advantages of using Beauveria formulations are their low toxicity to workers and low impact on some beneficial insects (Mingotti Dias et al, 2020), but their high cost and variable efficiency should be considered. Finally, is worth to mention that the propagule viability and infection of B. bassiana on CBB are favored in coffee plantations under managed shade compared to full sun exposure, possibly due to the interception of solar radiation and higher humidity (Edgington et al, 2000;Turro et al, 2013;Mariño et al, 2016).…”

Intraguild interaction between the entomopathogenic fungus Beauveria bassiana and two aphid predators

“…Similar results were found bySayed et al (2021) who studied the side effects of B. bassiana against C. undecimpunctata and Hippodamia variegate and reported that C. undecimpunctata and H. variegata remain unaffected by the presence of B. bassiana, as no significant changes have been documented. Also,Dias et al (2020) noted a low mortality rate among Ch. externa larvae treated with Buvariae.…”